Future-oriented Technologies and Concepts for an Energy-efficient and Resource-saving Water Management (ERWAS)


Prof. Dr. Theo Schmitt

Technical University of Kaiserslautern
Paul-Ehrlich-Str. 14
67663 Kaiserslautern

Tel.: +49 631 205-2946

Involved project parties

Map of the involved project parties

Logo arriveeWork packages of arrivee

The work program is composed of the partial steps and question formulations described below. For the realization of the described objectives, the project is divided into five interrelated work packages (AP) with an interdisciplinary approach (see figure 2). In figure 2 AP-leaders as well as project partners are additionally presented. The work packages partly build upon results achieved in a previous AP, sub sectors can be worked on independently and simultaneously.

AP 1 will examine the basis and the potential of control energy considering the known treatment processes without investment and operating expenses in a theoretical way. AP 2 will develop a concept for an optimized and energy efficient use of sewage gas in relation with excess energy from renewable energy generation. On this basis in AP 3 the adaption of an existing control and communication technology for the needs of the WWTP will be realized. The technology will be examined in a computer model of the WWTP Radevormwald in a virtual way, but also tested in real operations. The achievable control energy potential will be examined as well. AP 4 and 5 will analyse the social as well as the legal and economic questions related to the project.

AP 1: Basis establishing and potential analysis


Prof. Dr. Theo Schmitt, TU Kaiserslautern, Department of Urban Water Management, Paul-Ehrlich-Str. 14, 67663 Kaiserslautern


In AP 1 the potential of the supply of positive control energy (= switch on of energy generators and switch off of electricity users) and negative control energy (= switch off of energy generators and switch on of electricity users) and stabilized feed-in behaviour and purchasing habits for electrical power on WWTP with digester (CHP, compressed air-production, compressed air storage, monoincineration, power-to-gas technology) will be analysed fundamentally and be quantified by simulation tools.

In this context a description and determination of the flexibilities and the limiting conditions of the coupling elements between electrical network and WWTP as well as the determination of the relevant components of the WWTP will be realized. The nationwide potential of possible installation sites resp. suitable WWTPs will be estimated. The theoretical control energy potential will be identified basing on statistical data and will be compared with today control energy needs as well as with expected control energy needs in future.

Today marketing opportunities of stabilized purchase and entry load profiles by creation of superior balancing groups will be identified. The fundamental possibilities of avoided network expansion, supplying WWTP (high voltage, medium voltage, low voltage), will be described in view of the control and sales concept in general.

Furthermore in this AP the current version of national and international technical and legal guidelines for the integration of feeders, storage and load into the distribution network, e. g. ((BDEW 2008; VDE 2011; DIN EN 50160 (2011-02-00)) on different voltage power levels will be compiled. Next to current guidelines already foreseeable changes (e. g. national norms in draft status) will be considered.

AP 2: Concept and design


Karl-Heinz Lentz, iGas GmbH, Bonner Str. 305, 42697 Solingen


Local WWTPs can be integrated into the control energy market basing on different concepts. Those concepts will be developed and evaluated in this work package by the example of a WWTP of the Wupperverband. On principle, the energy surplus can be used in three scenarios with different efficiencies:

  • Energy surplus operation of the plant components, whereby the CHP is temporarily switched off and the surplus of sewage gas will be stored for a delayed use.

  • The conversion of the energy surplus through electrolysis into hydrogen and oxygen: The oxygen can be used in the activated sludge basin by reducing aeration energy demand. A possible use concept for the hydrogen includes (i) the incineration in a separated H2-CHP, (ii) the mixing to sewage gas with a common incineration in the CHP, (iii) the use as fuel for local vehicles as well as, (iv) a methanisation by use of CO2 from sludge digestion.

  • The production of compressed air and storage for continuous use in the activated sludge basin of the WWTP; by reduction of aeration energy.

Depending on possibilities of utilization on the spot as well as the efficiency of the conversion stages, figure 1 presents a conversion concept of renewable energy surplus.

AP 3: Interaction of market - network load - WWTP


Dr. Gerd Kolisch, Wupperverbandsgesellschaft für integrale Wasserwirtschaft mbH, Untere Lichtenplatzer Str. 100, 42289 Wuppertal


The interaction of network load, energy market and WWTP as well as the possible provision of positive and negative control energy will be tested and optimized with real data by the example of the WWTP Radevormwald of the Wupperverband. On this basis references and detailed action plans for the connection of WWTP technology to the virtual power plant will be derived.

AP 4: Market-oriented cost-benefit analysis


Ralf Simon, Transferstelle Bingen, Berlinstr. 107a, 55411 Bingen


In this work package the economic potential for WWTP will be estimated be means of an inventory of actual and future energy markets caused by a participation in the control energy market. The assessment of the energy policy of the market potential of the proposed storage and control system, further marketing opportunities ( supply and feed-in stability) and the avoided resp. necessary network expansion will be accompanied persuing the simulation of the plant concept and the test operations (AP 3).

With the help of cost-/benefit analyses the identified flexibilities in different concepts inter alia the convertibility of electrical power into other forms of energy (gas storage) and the delay of energy consumption of plants, e. g. digester, will be evaluated. On this basis recommended courses of action can be derived.

AP 5: Political and legal conditions


Prof. Dr. Theo Schmitt, TU Kaiserslautern, Department of Urban Water Management, Paul-Ehrlich-Str. 14, 67663 Kaiserslautern


ARRIVEE will be accompanied for the whole of the project term by a social scientific research work package focusing on energy policy (TU KL) and legal constraints / requirements (BBH) as well as the possibilities of their changes. The central question in this work package is: What are the political and legal requirements and constraints to increase the chances of the developed technological innovations in ARRIVEE to be implemented. Therefore the work package leader will also consider organizational (e. g. network expansion, load management, decentralized generation of renewable energy) as well as spatial criteria (e. g. effects of demographic change in the rural areas).

The knowledge gained for the development of the technological innovations in AP 2 & 3 will be regularly reflected and considered in the frame of the elaboration of this work package, as well as the identified basis information from AP 1 and the business analysis of AP 4. All project partners are involved in the final development of recommendations for action which can be derived from the project results.

The legal basics identified in AP 1 will be incorporated in a schematic representation differentiated according to areas of law as well as a detailed description considering the interplay of the different standards. The political, geographical and organizationally basis for the integration of WWTPs into the distribution network of regional energy supply will be analysed by TU KL and described in form of guideline internal to the project. These overviews should sensitize all other project partners timely how to consider the framework for the evaluation of possible approaches.